A color filter substrate is a member that includes colored layers of red (R), blue (B), green (G), and the like, which allows a display device such as a liquid crystal display device including the color filter substrate to provide color display. The liquid crystal display device provides display by controlling optical characteristics of light emitted from a light source using a liquid crystal layer included in a liquid crystal display panel. The liquid crystal display device typically includes an active matrix substrate, a color filter substrate, and a liquid crystal layer interposed therebetween, and further spacers are arranged between substrates to maintain the thickness (cell gap) of the liquid crystal layer.
A spherical spacer formed from plastics, inorganic materials, and the like, a column spacer formed from resin materials and the like, are known as the spacer. The column spacer is particularly excellent in high placement accuracy because it can be formed from a photosensitive resin by directly coating the resin on a substrate and then performing photolithography. This column spacer may be constituted by a black matrix layer (for example, refer to Patent Document 1). In addition to such a resin layer, the column spacer may be formed from a colored layer material and the like. That is, a multi-layer spacer is mentioned as the column spacer (for example, refer to Patent Document 2).
The color filter substrate is known to be typically produced in the following procedures.
A light-shielding layer that is formed from black matrix is formed between regions where a colored layer is to be formed later on a transparent substrate, first. Then, colored layers of red (R), blue (B), green (G), and the like, are successively formed at specific regions, respectively. Then, a transparent electrode (common electrode) for applying a voltage to a liquid crystal layer is formed over the entire substrate. Finally, a plurality of column (multi-layer) spacers are formed partly on the common electrode.
A liquid crystal display device is being rapidly developed, and improvements particularly in a method of forming a multi-layer spacer, a production method of a color filter substrate having a multi-layer spacer, and the like, are being particularly needed.
[Patent Document 1]
Japanese Kokai Publication No. 2003-228085
[Patent Documents 2]
Japanese Kokai Publication No. 2006-23733